Do you think victims of bullying who take revenge by killing the ones who tormented them be punished?

like the columbine highschool massacre(not sure what was the reason of the shootings though but i heard that these 2 kids were being bullied by the ones they killed) why should these persons be punished? i mean in some ways isn'tit punishing some sadistic monsters who would otherwise have gotten away with justice? don't tell me the usual crap about talking to parents principal 95 percent of the time it doesn't work